1. Field of the Invention
The present invention relates to gas turbine engines, and more particularly, to turbine rotors and an improved cover plate for sealing the connection between an airfoil blade and the disc of a turbine rotor.
2. Description of the Prior Art
Turbine rotors are normally constructed with a plurality of individual airfoil rotor blades mounted to the periphery of a rotor disc. Each airfoil blade includes a root that slides into an individual slot formed in the periphery of the disc. Cover plates are required to seal the connection and the area between the root and the blade platform that is at the inner boundary of the gas flow path. Such cover plates are relatively heavy and may affect the balance of the rotor. For instance, rivets or other fasteners are necessary for mounting the cover plates.
U.S. Pat. No. 4,343,594, issued on Aug. 10, 1982 to Perry, is an example of the prior art. This patent is concerned with the weight of the covers used to seal the area between the blade platform and the disc and proposes to connect the covers by using rivets passing through the disc between the roots. In fact, the rivets are an added weight necessitated by the covers.